The 'sports field tension membrane appearance' refers to the visual aspect of a tension membrane structure used in sports fields. These membranes are often made of durable materials like ETFE (Ethylene Tetrafluoroethylene) or PTFE (Polytetrafluoroethylene), providing a lightweight, translucent, and weather-resistant covering. They can enhance the aesthetic of the sports facility while providing shelter and protection against the elements.